function clickIE() {
if (document.all) {
return false;
}
} 
function clickNS(e) {
if (document.layers||(document.getElementById&&!document.all)) { 
if (e.which==2||e.which==3) {
return false;
}
}
} 
if (document.layers) {
document.captureEvents(Event.MOUSEDOWN);
document.onmousedown=clickNS;
} 
else{
document.onmouseup=clickNS;
document.oncontextmenu=clickIE;
} 
document.oncontextmenu=new Function("return false")